Homegrown: Globe willow cracks
I have noticed a large crack running most of the way down the trunk of our globe willow. It became very obvious when the wind was blowing and a large portion of the trunk was moving. Can this tree be treated and saved?
— Thanks, Barbara
Thanks for the photos you included. It looks to me like you have a condition common to many willow trees called included bark.
In a healthy and strong crotch, the branch comes off of the trunk at a relatively wide angle. In a case like this, at the junction where the top of the branch meets the trunk, there should be a “bark ridge,” a bulged-out raised ridge of tissue. This results in a good strong branch attachment.
However, when that crotch angle gets a bit too narrow, included bark can develop. Here, instead of bulging out and forming a bark ridge, the bark is folded down into the crotch. In this case, you have bark growing against bark and they will never knit together, resulting in a weak attachment that almost always ends up with the branch breaking off.
Your tree basically has two branches growing against each other and they just never will form a strong attachment. The easiest solution is to cut that branch off before it breaks off and causes a much worse problem.
I know that’s not your first choice for a solution, but it appears to me that you’re not removing more than 15 percent or 20 percent of the canopy and the tree is young — it will grow to fill in that area before you know it. Once the branch is cut off, I’d paint the open wound with orange or amber shellac.
An alternative to cutting the branch off is to “cable” the branch. Basically, this is drilling through both the branch and the trunk several feet above the juncture (I’d probably go between 5 feet and 8 feet in your case) and screwing in an eye-bolt in each. You want to put a series of increasingly larger metal washers on both ends of the bolts to support the nut as you tighten them in.
You then string steel cable between the two bolts putting a turnbuckle in the middle to adjust tension. Pull the cable as tight as you can and secure it to each end. The turnbuckle can be used initially to increase tension and to take up any slack that develops in the cable over time.
Cabling a tree is simply providing a mechanical support to a weak branch. It’s not a perfect solution — you have to maintain tension in the cable over the years and you run the risk of introducing disease problems into the willow when you install the bolts. Honestly, I think your best course of action is to remove that branch.
While you’re at it, take a good look at the rest of the tree to make sure that there are no other branch junctures that threaten to develop included bark. Willows are especially prone to this problem and dealing with it early on while the branches are small will save you lots of grief and work down the road.
I hope this is making sense to you. It’s hard to explain in words and if I’m not making sense, come on by the nursery and I can draw some pictures that explain this better.
Could my locust tree have been frozen during April’s cold nights? It is covered with little dead leaves instead of new green ones. Will it come out of it with time?
— Thanks, Judy
Your tree simply got hit by those chilly nights we had. Some of the later budding plants like ash, catalpa, flowering locust, grapes and honeylocust all got burned by that frost. The tree will push out new growth and the tree will be fine. It’s a setback, but a minor one. Just hang in there and treat it like nothing’s wrong.